final keyword and Anonymous Inner Class (AIC)

Hello, So I already went through some discussions regarding final and AIC but I still have certain doubts and if somebody can help me with this then it would be great!

1. Is it important to write the final keyword with a data type- variable even if I am just displaying the value or reading it but nowhere in the AIC changing the value?

I went through a blog and it says "In java 8, since we are only accessing the value in AIC, then the variable need not be declared "final". But when I am doing this in Android Studio, it is not allowing me to do so.

1. Also, if I define the variable to be an instance variable (class) and change the value of instance variable in the AIC, will the changes persist outside the inner class?

Again, I went though the blog "http://blog.brendanlacanette.com/2015/08/variable-is-accessed-within-inner-class.html" and it says the changes will persist and when I tried this in Android Studio using Log, the value didn't change.

``` Android, Java

public class FunFactsActivity extends AppCompatActivity {

private TextView textView;
private Button showFactButton;
private RelativeLayout relativeLayout;
int a = 5;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fun_facts);

    textView = findViewById(R.id.factTextView);
    showFactButton = findViewById(R.id.showFactButton);
    relativeLayout = findViewById(R.id.mainLay);


    showFactButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            ChangeFact changeFact = new ChangeFact();
            String fact = changeFact.showFact();
            ChangeColor changeColor = new ChangeColor();
            int color = changeColor.color();
            textView.setText(fact);
            textView.setTextColor(color);
            showFactButton.setTextColor(color);
            relativeLayout.setBackgroundColor(color);
            Log.d("Value", a + "");
            a = 7;

        }
    });
    Log.d("New Val", a + "");

}

}

Probably, I am understanding and applying the blog wrong. Can someone please answer these questions for me so that I can have a better understanding? Thanks in advance! :)